1. Field of the Invention
The present invention relates to a transmission, and, more particularly, to a hydraulic regenerating low-speed operating power shift transmission for use in a work vehicle.
2. Description of the Related Art
Work vehicles, such as wheel loaders, are often equipped with a torque converter and a multi-speed power shift transmission. These types of vehicles often include a shuttling method allowing for a rapid change in direction requiring deacceleration and acceleration in an opposite direction. The shuttling method is utilized to provide effective forward and reverse motion for such vehicles as wheel loaders as they approach a pile of aggregate and as they quickly change direction. The lifting bucket is then used to secure the aggregate and the transmission is shuttled into a reverse direction to leave the pile of aggregate. The shuttle mechanism is then shifted to the forward direction to approach a dumping point, such as a bed of a dump truck. The shuttling causes the transmission direction to be reversed, causing the engine to drive the vehicle to a stop, then in the opposite direction. Vehicle brakes are generally used in the decelerating of the vehicle. For low-speed operation, the engine speed must be kept high to drive the other hydraulic systems. This causes a high slip speed in the torque converter, which consumes engine power and fuel. Although the current method is effective, it is very inefficient when the vehicle is shuttling back and forth during low-speed operation.
What is needed in the art is a transmission that is not only effective but efficient in shuttling operations and during low-speed movement of the work vehicle.